A conventional circuit board module, including a terminal board, is inserted into and extracted from a socket when required. For example, the terminal board is fixed to one end part of a circuit board by solder. Electronic components are mounted on a surface of the circuit board. The terminal board has a first surface opposing the surface of the circuit board, and a second surface on a side opposite from the first surface. Socket-connection pads for making contact with and electrically connecting to terminals of the socket are provided on the second surface of the terminal board. In addition, pads, having the same size as the socket-connection pads, are provided on the first surface of the terminal board. The pads provided on the first surface of the terminal board are connected to pads provided on the surface of the circuit board by solder. For example, Japanese Laid-Open Patent Publication No. 2003-046273 proposes a circuit board module similar to that described above.
In the circuit board module, the terminal board is required to connect to the circuit board with a high positional accuracy and a high degree of parallelism, in order to improve reliability of the connection between the circuit board module and the socket. However, in the conventional circuit board module, the positional accuracy and the degree of parallelism of the terminal board with respect to the circuit board may not always be satisfactory.